Asphalt-surfaced roadways facilitate vehicular travel. Depending upon usage density, base conditions, temperature variation, moisture variation, and/or physical age, the surface of the roadways can eventually become misshapen, non-planar, unable to support wheel loads, or otherwise unsuitable for vehicular traffic. To rehabilitate the roadways for continued vehicular use, worn asphalt is removed in preparation for resurfacing.
Cold planers, sometimes also called road mills or scarifiers, are machines that typically include a frame supported by tracked or wheeled drive units. The frame is configured to provide a mount for an engine, an operator's station, and a milling drum. The milling drum, fitted with cutting tools, is turned through a suitable interface by the engine to break up the surface of the roadway.
In a typical configuration, multiple spiraling rows of cutting tools are oriented on an external surface of the milling drum to converge at a location on the drum corresponding to a location of a material removal component of the machine. The individual cutting bits may be mounted to at least one tool mounting block by tool holders. The tool holders are often mounted to the tool block using a friction or interference connection. For example, U.S. Pat. No. RE44,690 to Sollami discloses a bit holder utilizing a tapered shank and an axially oriented slot through the side wall of the shank to allow an interference fit. U.S. Pat. No. RE44,690 discusses a bit holder with a mating bit block utilizing a slight taper in a bit block bore, and a tapered shank on the bit holder that includes a second larger diameter tapered distal segment that combines with an axially oriented slot through the side wall of the bit holder shank to allow a substantially larger interference fit between the distal tapered shank segment and the bit block bore than previously known. When inserting the bit holder in the bit block bore, the distal first tapered segment resiliently collapses to allow insertion of that segment into the bit block bore. A second shank tapered portion can be located axially inwardly of the first distal tapered portion. The dual tapered shank allows the insertion of the bit holder in the bit block with an interference fit that provides a secure mounting of the bit holder in the bit block.
Through use of the milling drum, the tool holders can be damaged or broken. Current tool holder designs may require the machine being taken out of service frequently or for long periods to replace lost or broken tool holder. The tool holder and milling drum of the present disclosure solve one or more of the problems set forth above and/or other problems in the art.